Flavodoxin



Flavodoxin (FDX) is a bacterial protein which contains flavin mononucleotide (FMN) or flavin adenine dinucleotide (FAD). It participates in nitrogen metabolism and reduces N2 to NH3 while changing from its oxidized quinone state FDX-ox via semiquinone FDX-sq to its reduced hydroquinone state FDX-red. NrdI is a FDX which is involved in ribonucleotide reduction. WrbA (Tryptophan Repressor-Binding Protein) is also FDX. In E. coli there are 2 distinct FDX I and II. The images at the left and at the right correspond to one representative FDX structure, i.e. the crystal structure of apo-flavodoxin from Helicobacter pylori (2bmv). The space filling objects are of chloride ion and benzamidine.

Apo FDX
2kqu, 1dx9 – AnFDX (mutant) apo – Anabanea – NMR

2bmv – HpFDX apo - Helicobacter pylori

3d7n – FDX apo – Agrobacterium tumefaciens

2rg1 - EcFDX WrbA apo - Escherichia coli

2hna, 2hnb – EcFDX apo – NMR

1qhe, 1ftg – nFDX apo – Nostoc

1bu5 – DvFDX apo+riboflavin - Desulfovibrio vulgaris

FDX containing FMN oxidized (quinone)
3f6r, 3f6s, 3kap – DdFDX-ox - Desulfovibrio desulfuricans

1ag9 – EcFDX-ox

1flv – nFDX-ox

1xyy, 1j9g, 1c7f, 1akr, 1akt, 1akw – DvFDX-ox (mutant)

2fx2, 3fx2, 4fx2, 5fx2, 1fx1 – DvFDX-ox

1czk, 1czr – SeFDX-ox (mutant) - Synechococcus elongates

1czn – SeFDX-ox I

1ofv – SeFDX-ox II

1czu, 1d03 - SeFDX-ox II

2fdx, 1fld, 1fvx, 2fax, 3nll, 4nll, 4nul, 5nll – CbFDX-ox (mutant) - Clostridium beijerinckii

2fcr – FDX-ox – Chondrus crispus

1fue – HpFDX-ox

FDX containing FMNH (semiquinone)
2x2o, 2x2p – NrdI-sq – Bacillus cereus

3kaq, 3f90 – DdFDX-sq

1xt6, 1wsw, 1xyv, 1akv, 1wsb - DvFDX-sq (mutant)

1czh, 1czl - SeFDX-sq (mutant)

2fox, 5nul– CbFDX-sq

FDX containing FMNH2 (hydroquinone)
2fz5 – FDX-red – Megasphaera elsdenii – NMR

1c7e, 1aku, 1akq - DvFDX-red (mutant)

1czo - SeFDX-red (mutant)

1d04 – SeFDX-red

1fla, 1fln, 2flv, 2fvx, 5ull, 6nul – CbFDX-red (mutant)

Other FDX
3esx, 3esy, 3esz, 2v5u, 2v5v, 1obo, 1obv - AnFDX (mutant)

1rcf, 1flv - AnFDX

2wc1 – FDX – Rhodobacter capsulatus

2w5u – HpFDX+C3 inhibitor 1fue - HpFDX

2kaq – DdFDX

2r97, 2r96 – EcFDX WrbA

1ahn – EcFDX

2q9u – FDX di-iron – Giardia intestinalis

2ark – FDX – Aquifex aeolicus

1yob – FDX II – Azotobacter vinelandii

1j9e, 1f4p, 1i10, 1azl – DvFDX (mutant)

1j8q - DvFDX